Arachne Reef - Pacific Northwest
Arachne Reef is one of those spots that just keeps giving. We’ve logged countless dives here and it never fails to surprise. Drop down, and you’re instantly enveloped in a forest of kelp, swaying gently in the subtle surge. The light filters through, painting shifting patterns on the rocks below. We’ve spent whole dives just watching the ballet of the Snake Pricklebacks weaving through the fronds, or spotting the brilliant orange of a Sweet Potato Sea Cucumber clinging to the rock face. Our favourite time to dive Arachne is on a slack tide, early in the morning. That’s when the resident Red Rock Crabs are most active, scuttling across the seabed, and you often catch the smaller Humpy Shrimp and Shortscale Eualids out foraging. Look closely into the crevices and you’ll find Prickly Sculpins perfectly camouflaged. We’ve even been lucky enough to hear the distant calls of Orcas from the surface, though seeing them underwater is a rare treat. It’s a site that rewards slow, meticulous divers. Expect to come up a little colder but absolutely buzzing with what you’ve seen.
- Location
- Pacific Northwest, United States, North America
- Coordinates
- 48.682940, -123.302620
- Type
- reef
Marine Protected Area: Kellett Bluff Voluntary No-take
Best Time to Dive in Pacific Northwest
The warmest water temperatures in Pacific Northwest occur in August, averaging 16.5°C (up to 15.6°C). The coolest conditions are in February at 6.9°C.
Monthly Water Temperatures
- January: 7.1°C (air: 6.3°C)
- February: 6.9°C (air: 4.5°C)
- March: 7.7°C (air: 6.6°C)
- April: 9.5°C (air: 8.7°C)
- May: 12.0°C (air: 11.7°C)
- June: 14.0°C (air: 13.7°C)
- July: 15.7°C (air: 14.9°C)
- August: 16.5°C (air: 15.7°C)
- September: 14.3°C (air: 14.0°C)
- October: 11.4°C (air: 10.5°C)
- November: 8.8°C (air: 7.4°C)
- December: 7.7°C (air: 5.5°C)
Nearby Dive Sites in Pacific Northwest
- 100 Foot Rock
- Alki Beach Park
- Alki beach Seattle ferry north
- Am/Pm Beach - 13m (shore)
- Ansell Point Dive Site - 5-20m (shore)
- Arachne Reef - 5-20m (reef)
- Arbutus Island - 10-30m (shore)
- Arbutus Point - 23m
- Atkins Reef (reef)
- Atrevida Reef (reef)
- Barnard Castle - 15-35m (pinnacle)
- Bell Island
- Blake Island Reef (reef)
- Blind Reef (reef)
- Boiling Reef (reef)
Nearest Dive Centres to Arachne Reef
Marine Life in Pacific Northwest
Home to 38 recorded species including 18 reef fish, 7 crabs & lobsters, 3 whales & dolphins, 2 sharks & rays, 2 clams & mussels, 2 sea urchins.
Notable Species
- Pacific herring (Clupea pallasii) - Reef Fish
- coho salmon (Oncorhynchus kisutch) - Reef Fish
- Spiny Dogfish (Squalus suckleyi) - Sharks & Rays
- Chinook (Oncorhynchus tshawytscha) - Reef Fish
- Dungeness Crab (Metacarcinus magister) - Crabs & Lobsters
- Common shore crab (Carcinus maenas) - Crabs & Lobsters
- red salmon (Oncorhynchus nerka) - Reef Fish
- California Spot Prawn (Pandalus platyceros) - Crabs & Lobsters
- Slender Crab (Metacarcinus gracilis) - Crabs & Lobsters
- Rainbow Trout (Oncorhynchus mykiss) - Reef Fish
- Whiting (Merluccius productus) - Reef Fish
- Pacific krill (Euphausia pacifica) - Crabs & Lobsters
- Common Seal (Phoca vitulina) - Whales & Dolphins
- Eulachon (Thaleichthys pacificus) - Reef Fish
- Red Rock Crab (Cancer productus) - Crabs & Lobsters
- Spotted Ratfish (Hydrolagus colliei)
- Calico salmon (Oncorhynchus keta) - Reef Fish
- Slender Sole (Lyopsetta exilis) - Reef Fish
- Pacific Geoduck (Panopea generosa) - Clams & Mussels
- Olympia oyster (Ostrea lurida) - Clams & Mussels
Recommended Packing List for Arachne Reef
Based on average water temperature of 11.0°C, currents 7 cm/s.
- Wetsuit (5-7mm) - recommended for 11°C water
- Hood & Gloves (3-5mm) - helps retain warmth
- Mask - essential for every dive
- Fins
- BCD - buoyancy compensator
- Regulator - your most safety-critical piece of gear
- Dive Computer - tracks depth, time, and NDL
- Surface Marker Buoy (SMB) - essential for boat pickups
- Dive Torch - useful for crevices and colour at depth
- Underwater Camera - capture your diving memories